Regulator



Feb. 5 1924. 1,482,791

G. M. HAFER REGULATOR Filed Sent. 14. 1921 2 Sheets-Sheet 1 8 EZZZ QJZ.ii /6 m Feb. 5 1924.

s. M. HAFER REGULATOR Fil'ed Sept. 14 1921 2 Sheets-Sheet 2 A9 /i I Ai/5 26 y L ummnlm Patented Feb. 5, 1924.

UNITED STATESv GUY M. KLFER, OF DETROIT, MICHIGAN,

ASSIGNOB TO KOSKINS MANUFACTURING COMPANY, OF DETROIT, MICHIGAN, ACORPORATION 01 MICHIGAN.

REGULATOR.

Application filed September 14, 1821. Serial No. 500,718.

To all whom it may concern:

Be it known that I, GUY M. Harm, a citizen of the United States, residinat Detroit, in the county of Wayne and tate of Michigan, have invented anew and useful Improvement in Regulators, of which the following is aspecification.

This invention relates to regulators and is particularly adapted to beused on furnaces and the like for automatically controlling thefurnace-heating means so as to maintain the temperatures of the furnace'nearly constant.

The invention is clearly set forth in the following specification andshown in the accompanying drawings, in which Figure 1 is a partial planview of the regulating mechanism; Fig. 2 is a front elevation of thesame; Fig. 3 is a side elevation of'Figure 1; Figures 4, 5 and 6 arefront elevations showing the operating plungers in various positions;Figure 7 is a diagrammatic view of the regulating mechanism, and Fig. 8is a front elevation of a modified form of plunger mechanism.

This mechanism is illustrated as applied to a galvanometer having aneedle 10 which oscillates over a scale 11 in a well-known manner. Onthe upper edge of the scale 11 is formed a smooth ledge 12 and a pin 13is carried by the needle and swings above this ledge.

The main frame 14 of the galvanometer carries a gear 15 which isjournalled thereon, the center of this gear corresponding to the axis ofthe needle 10. The gear 15 carries a lug 16 to which an arm 17 ispivotally connected by means of a pin 18. This arm is normally held inthe raised position, as shown in Figure 3, by means of the flat spring19.

The outer end of the arm 17 overlies the ledge 12 and has three plungers20, 21 and 22 which are vertically slidable therein.

The lower ends of the plungers and 22 are enlarged and retain a plate 23through which they pass. Sprin 24 serve to hold these plungers in theirowermost position, which is fixed b means of pins 25, as shown in Figure3, which pass thru the upper ends of the plungers.

- The u per ends of these plungers arealso necked own and a flat metalspring 26 is hingedly mounted upon pins 27 at the outer end of the arm17. The upper edge of the spring 26 is so placed as to yield as any ofthese plungers are raised and falls into the neck portion so as toretain them in the raised position until it is released.

A pair of switch-contacts 28 and 29 are mounted so as 'to be insulatedfrom each other and from the arm 17 and have their outer movable endsimmediately over one of the lungers, so that as the plunger is raised tey will be moved into enga ent.

The central pair of contacts which are operable by the plunger 21 areshown in the center of Figure 7 and are connected to 'a source ofcurrent 30 and a lamp 31 in series therewith.

In this same figure, contacts 28 and 29 which are operable by theplunger 20 are placed in series with a suitable source of electriccurrent 30, a lamp 31 and a solenoid 32. This solenoid has a core 33 towhich is pivotally connected a pawl 34 which has a slot 35 which isslidable over the stationary pin 36.

It will thus be seen that when the switch 28, 29 is closed, current willflow thru the solenoid 32 in the core 33 and move the pawl 34. Owing tothe angularity of the slot 35, the outer end of the pawl will be drawndownwardl and to the left and will engage a tooth o the ratchet 37,thereby moving the rheostat arm 38 to the left.

The contacts 28" and 29", also shown in I Figure 7, are likewiseoperable by means of the plunger 22. These contacts likewise are placedin series with a suitable source of current 30, a lamp .31 and asolenoid 32. This solenoid has a core 33 which is pivotally connected toa pawl 34 which operates a ratchet 37 which is connected to the ratchet37 but which operates in the reverse direction.

It will thus be seen that when the plunger 22 is raised the switch28",29 will be closed and the solenoid 32 will be actuated to move therheostat arm 38 one notch to the right.

The furnace (not shown) is heated by means of a resistance coil 39, asshown in Fig. 7, which is placed in series with any suitable source ofcurrent 40 and the rheostat which has been reviously described. Anelectric pyrometer not shown) is placed in the furnace and connected tothe galvanometer in a well-known manner.

The shaft 41, as shown in Figure 2, is

driven at a uniform rate of speed by an suitable means and carries a cam42 whic periodically raises the cam follower 43 and the rod 44. This rodis connected to. the outer end of a lever which is pivotally mounted at46 near its center. The opposite end of the lever 45 overlies a pin 47which is slidably mounted so as to engage the arm 17.

The method of operation of this device is as follows:

When the electric furnace has been in operation for sometime so as tohave reached nearly a stationary temperature, the arm 17 is turned sothat its pointer 17 indicates the temperature of the furnace which it isdesired to maintain. This is done by means of a pinion 15 which isturned by means of the thumb-nut 15".

The arm 17 is periodically depressed by means of the cam 42. Assumingthat the in 13 is beneath the plunger 22, as shown in Figure 4, as thearm 17 is lowered the plunger 22 will engage the pin 13, depressmg ituntil it strikes the ledge 12. The ot er plungers 20 and 21 will then befurther lowered while the plunger 22 is pushed up into engagement withthe spring 26.

The contacts 28 and 29 are then forced into engagement, closing thecircuit and actuating the solenoid 32". This will cause the rheostat arm38 to be drawn to the right, thereby cutting out some of the resistancecoils 38 and increasing the current flowin thru the heating coil 39. Thetendency will therefore be to increase the temperature of the furnacewhich in time will manifest itself by increasing the current flowingthru the pyrometer, thereby swinging the galvanometer needle 10 to theleft, as shown in Figures 1, 2 and 4.

During the time that the switch 28", 29" is closed the lamp 31 willremain lighted, indicating that the plunger 22 was actuated. Thisplunger corresponds to a temperature in the furnace which is belownormal, while the plunger 21 corresponds to a normal temperature and 20to a temperature above normal. These temperatures are indicated bydifferent colored lights 31, 31 and 31", so that the operator, who maybe at some distance from the instrument, will know from the color of thelight which plunger was the last one actuated and consequently willindicate to him whether the temperature of the furnace is normal orwhether it is above or below normal.

As the temperature in the furnace increases, the pin may be moved to theposition shown in Figure 5 and upon depressing the arm 17 the plunger 20will be raised, thereby releasing any other plunger which may have beenin a raised position. The solenoid 32 will then be actuated and therheo'stat arm 38 will be moved to the left,

thereby decreasing the current flowing thru the heating coils 39, withthe result that the temperature will again be brought nearer normal.

At certain points, as shown in Fi ure 6, the pin 13 may be immediatelyun er two of the plun rs, in which case they will both be raised. n thiscase, both of the lights 31 and 31" will be lighted, indicating thatboth plungers have been actuated and that th temperature of the furnaceis very nearly normal.

In Fig. 8 is shown a modification of the mechanism shown in Fig. 6 inwhich the central plunger 21 is securely held on the arm 17. The bottomof this plunger is beveled at both sides and the pin 13 is rounded ontop so as to cause the arm 17 to swing to one side or the other if theplunger strikes the pin. In this case, only two lighting circuitscontrolled as previously explained by the plungers 20 and 22 are Theforegoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, but the appended claims should be construed as broadly aspermissible in view of the prior art.

What I claim as new, and desire to secure by Letters Patent, is-

1. In an electric pyrometer for furnaces, a galvanometer having anoscillating needle, a pin carried by said, needle, a ledge over whichsaid pin oscillates, a member having a plurality of plungers slidablymounted therein, said plun ers overlying the path of said pin, means orperiodically depressing said member to cause said pin to actuate one ofsaid plungers, an electric circuit having a switch which may be closedby one of said lungers as it is actuated, and means opera le by saidcircuit for varying the temperature of said furnace.

2. In an electric pyrometer for furnaces, a galvanometer havin anoscillatin needle, a pin carried by sai needle, a le go over which saidpin oscillates, a member having a plurality of plungers slidably mountedtherein, said plungers overl in the path of said pin, means for perioica ly depressing said member to cause said pin to actuate one of saidplungers, an electric circuit having a switch which may be closed by oneof said plungers as it is actuated, electric resistance coils for heatinsaid furnace, and means operable by said circuit for varying the currentpassing thru said coils.

3. In an electric pyrometer for furnaces, a galvanometer having anoscillating needle, 9. pin carried by said needle, a ledge over whichsaid pin oscillates, a member having a plurality of plungers slidablymounted therein, saidplungers overl in the path of said pin, means forperiodica y depressing said member to cause said pin to actuate one ofsaid plungers, an electric circuit having a switch which may be closedby one of sa1d plungers as it is actuated electric resistance coils forheating said furnace, a rheostat in series with sa1d coils, a ratchetoperabl connected to said rheostat, and a solenoi in said circuitoperably connected to said'ratchet.

4. In an electric pyrometer for furnaces, a galvanometer havin anoscillatin needle, a pin carried by sai needle, a 1 ge over which saidpin oscillates, a member having a plurality of plungers slidably mountedtherein, said plungers overlying the path of said pin, means forperiodically depressing said member to cause said pin to actuate one ofsaid plungers, an electnc circuit having a switch which may be closed bysaid plun er as it is actuated, and means operable y one of saidcircuits for lowering the temperature of the furnace and means operableby another of said circuits for raising the temperature of the furnacewhen sa1d circuits are selectively closed by their plungers.

5. ii an electric pyrometer for furnaces, a galvanometer havin anoscillatin needle, a pin carried by sai needle, a le go over which saidpin oscillates, a member havin a'plurality of plungers slidably mounttherein, said plungers overlying the path of said pin, means forperiodical y depressing said member to cause said pin to actuate one ofsaid plungers, a switch operable by each plunger, an electric circuitconnected to said switch, electric resistance coils for heating saidfurnace, a rheost-at in series with said coils, and means operable bysaid circuit for moving said rheostat as the galvanometer moves eitherway from a predetermined position.

6. In an electric pyrometer for furnaces, a galvanometer havin anoscillatin needle, 'a pin carried by sai needle, a le ge over which saidpin oscillates, a member having a pluralit of plungers slidably mountedtherein, sa1d plungers overlying the path of said pin, means forperiodically depressing said member to cause said pin to actuate one ofsaid plungers, a switch operable by each plunger, an electric circuitconnected to said switch, electric resistance coils for heating saidfurnace, a rheostat in serieswith said coils, means 0 rable by saidcircuit for moving said r eostat as the galvanometer moves either wayfrom a predetermined position, and a si al means in each of saidcircuits for in icating which circuit is actuated.

GUY M. HAFER.

